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Oxygen Saturation (Arterial) via Pulse Oximetry Probe

Published: August 9, 2026Updated: August 16, 2026

This test measures the percentage of oxygen bound to hemoglobin in your blood arteries using a small sensor attached to your finger, toe, or ear. It’s a quick, painless way to check how well your body is delivering oxygen.

Quick summary

["Quickly assesses oxygen levels in your bloodstream for early detection of low oxygen conditions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
73800-5
Short code
SaO2% Device SaO2% sensor wrap size
Synonyms
SaO2% Device SaO2% sensor wrap size
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

How This Test Works

A small sensor (probe) is placed on your finger, toe, or ear. The sensor emits light that passes through your blood vessels, measuring how much oxygen is bound to hemoglobin. This measurement is converted into a percentage called oxygen saturation (SpO₂).

What to Expect During the Test

The test is very simple and takes just a few minutes. You may feel a slight pressure or mild discomfort from the sensor, but no needles or blood draws are involved. You can usually resume normal activities immediately after.

When This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like shortness of breath, fatigue, rapid heartbeat, or if you’re at risk for conditions like low oxygen levels (hypoxia), heart or lung diseases, or during certain medical procedures.

Possible Results and Next Steps

Results are typically reported as a percentage (e.g., 95%). Normal values can vary slightly, but generally, healthy adults have SpO₂ levels between 95% and 100%. If your result is lower than expected, your provider may order additional tests or treatments to address potential issues.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

SpO₂ (Pulse Oximetry)

Frequently asked questions

Why is this test important?
This test is crucial for monitoring oxygen levels in real-time, especially for patients with chronic lung diseases, heart conditions, or those undergoing anesthesia. It helps detect low oxygen quickly, allowing for prompt medical intervention if needed.
What if my SpO₂ is low?
A low SpO₂ reading may indicate a problem with your lungs, heart, or circulation. Your provider will review your symptoms, medical history, and other test results to determine the cause and next steps, which could include further testing or treatments like oxygen therapy.
Does this test require fasting?
No, this test does not require fasting. It’s a non-invasive procedure and can be done anytime during the day.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy